Palliative Care and Cancer Pain

Pain is a high frequency symptom occurring in 50% of cancer patients at diagnosis increasing to 80% of patients with advanced-stage cancer. In the context of a complete palliative care evaluation, proper pain assessment requires measurement of pain intensity, delineation of opioid responsiveness, as well as clarification of the impact of pain on patients' psychological, social, spiritual, and existential domains. Pain is effectively managed by application of the World Health Organization (WHO) analgesic ladder which classifies pain intensity according to severity and recommends analgesic agents based on their strength. Step 1 analgesics are reserved for mild pain and include nonopioid analgesics such as acetaminophen, nonsteroidal antiinflammatory or an adjuvant analgesic if necessary. Step 2 analgesics target those patients experiencing mild to moderate pain who are already taking a nonopioid analgesic but are experiencing poor analgesia. Step 2 agents include acetaminophen products containing hydrocodone, oxycodone, codeine, as well as tramadol. Patients with moderate to severe pain require strong analgesics belonging to Step 3 of the WHO analgesic stepladder. Step 3 opioids include morphine, hydromorphone, fentanyl, levorphanol, methadone, and oxycodone. Familiarity with opioid pharmacokinetics, equianalgesic dosing, and adverse effects is necessary for safe and effective use. The appropriate use of adjuvant analgesics such as antiepileptic drugs, antidepressants, and local anesthetics enhances the use of opioids, especially in cases where opioid responsiveness may be in question, such as with neuropathic pain. Interventional techniques play a role in cancer pain management when conventional analgesic therapies are ineffective or cause significant adverse effects.